


The Supernatural Instruments

by Bookfairy



Category: Mortal Instruments Series - Cassandra Clare, Shadowhunters (TV), Supernatural
Genre: Crossover, Demons, Supernatural - Freeform, Supernatural/The Mortal Instruments, the mortal instruments - Freeform, tmi
Language: English
Status: In-Progress
Published: 2016-03-28
Updated: 2016-03-28
Packaged: 2018-05-29 19:19:22
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,148
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6389848
Author URL: https://archiveofourown.org/users/Bookfairy/pseuds/Bookfairy
Summary: <blockquote class="userstuff">
              <p>You are a Shadowhunter, on a hunt with your best friend Jace Lightwood/Herondale. That’s when you stumble across a pair of mundane hunters, Sam and Dean Winchester. Of course you’ve heard much about them, with them starting the Apocalypse they were well-known in the Shadow World. Needless to say, you weren’t too happy to see them on your hunt.</p>
            </blockquote>





	The Supernatural Instruments

**Author's Note:**

> Hey there!  
> This is the first chapter of my Supernatural/Shadowhunters crossover. The two fandoms don't collide perfectly because there is different lore about the demons and stuff, but I tried to mix them as smoothly as possible.  
> This is my first fanfiction ever, so please feel free to comment advise or criticism, I want to learn and improve my writing. Also english isn't my first language so when you notice anything that's wrong, you can comment that too :)  
> And of course if you have any ideas of what could happen next, I would be happy to read some inspirations! :)  
> Now you can imagine yourself into this story. I hope you enjoy it!
> 
> Y/N= Your Name

„Jace, would you mind to hurry up a bit? You can admire your reflection at home!“ you hissed behind your back, while cautiously walking through the dark corridor of the building you‘ve entered minutes before. You knew there were demons in here, you just didn’t know where. Jace jogged up next to you, with a smug smile on his face. „Can you judge me? I mean, look at me“ You seriously restrained the urge to punch him right in the face. That’s what it’s like to be best friends with Jace Lightwood, but over the years you’ve had developed patience with the rude Shadowhunter. You knew his other sides, which made him so loveable for you. You said nothing, and proceeded to look in the rooms to the left and right down the corridor, but there was nothing in them. „There has to be something here. Where-“ you turned silent when you heard voices from downstairs. Jace sighed. You both paced to the stairs at the end of the corridor, without making a single sound, because of your soundless runes. Now you could understand the voices. „Dean, I don’t think anyone is here. This building is empty.“ The voice came from a tall man, with shoulder-long brown hair. After him, a slightly smaller entered the room underneath you. „Well, Cas said they’re here, so I guess we have to look around more,“ the smaller one said. He had shorter, blonde hair and lots of freckles in his face. You and Jace exchanged a look. Jace mouthed „Mundanes“, with a priceless annoyed expression on his face. You couldn’t keep yourself from grinning. But the grin was quickly swiped off your face when the two boys downstairs were pushed against the walls by an invisible force. You grabbed the necklace you were wearing-the red pendant started to heat up and glow, which meant that demons were near you. Two men entered the room downstairs. „Well, well, well, would you look at that, the Winchesters honour us with their presence. How did we deserve this? “, the one man asked the other. But what the mundanes probably couldn’t see was that the two weren’t men, they were demons. Du’sien demons, to be specific. But the mundanes, the Winchesters apparently, didn’t seem surprised. They looked like they were waiting for something. Wait, Winchester? You’ve heard that name before, but you couldn’t remember where. The two demons stepped forward, and obviously wanted to attack them, but they suddenly stopped. The Winchesters dropped off the wall and landed on the ground. „WHAT? What did you do?“ one of the demons yelled. The taller, but apparently younger, Winchester laughed, and huffed „Next time, you should watch your step.“ The demons looked down, and finally realised that they walked right into a devil trap. „I don’t think there will be a next time“, the older brother said with a mocking grin.  
You turned your head to Jace, because you honestly didn’t know what to do right now. These people were obviously hunters, but you couldn’t let them kill the demons. That was your job, and you knew Jace would be fuming if mundanes interfered with your hunt. Besides, it was practically your task on earth to protect the humans, and letting them fight with demons while you’re watching was probably not de definition of „protecting“. But Jace wasn’t there anymore. You looked around to find him, but he was nowhere to see. You looked down again, and saw the two brothers performing an exorcism on the two demons. Suddenly, a man in a black suit entered the room. The Winchesters stopped. „Crowley? What are you doing here? “„I was supposed to have an important meeting. But of course, the Winchesters choose to show up and mess everything up. We all know that’s your special skill. “, Crowley snapped back. He scratched the devils trap with his foot, so the two demons inside it could move again. „This is beneath me. Have fun with them, boys.“ He vanished. The demons started to regenerate from the exorcism, and slowly approached the Winchesters again. 

That was the point where you decided to do something. You jumped over the railing, and landed in the room downstairs. Needless to say, everyone was surprised. You wasted no time, and started attacking the demons with your Seraph blade. You struck a blow at the demon you were fighting, and it hissed at you angrily. Then, the Winchesters started to move again and joined the fight. The older brother attacked one of the demons with a knife, and you noticed that he was a really good fighter, at least for a mundane. He shot a curious look at you, but he immediately payed the price for the short distraction. The demon hit him so hard that he flew against the wall. You heard an ugly cracking noise and a groan, but you didn’t turn around. You quickly finished the demon, and spun around to the other one. The younger brother was in a hard fight against the second demon, but he seemed like he could handle it. You allowed yourself to turn around and look at the older brother. But before you even completely turned around, all the doors around the room flew open, and at least a dozen demons spilled out of them. Adrenaline filled your body, and you laughed. The more the merrier. You looked up, and shouted „JACE! Get your lazy ass down here! “Jace landed right next to you, chuckling. „All right, all right tiger, calm down. I’m here to save the day“ This time, you couldn’t keep yourself from punching him. „Ouch,” he laughed and ruffled your hair, then ran off to the fight. It was remarkable how quickly his mood changed when there was something to kill. You pushed the younger Winchester brother aside, ignoring his protest. Jace and you could handle this on your own. You turned your back to Jace, and started to fight. 

You two were such a perfect team, you didn’t need to look at him to know what he was doing. Moments like this were special to you, because it showed how well you knew each other. You noticed the two brothers joining the fight again, but this time you just let them. If they were stupid enough to mess around with demons, then that was none of your business. Right now all you needed to care about was that you were surrounded by demons. You spun around in different directions, leaving a pile of ashes with every demon you stabbed. And you saw Jace doing the exact same thing. He really could fight like the devil-you always felt a little proud watching him fight. When there was nothing left for you and your blade, you looked around the room. You saw the two Winchesters each fighting with the two demons that were left. Jace looked at you, crossed his arms and raised one eyebrow. “I hope these two pull off a good show. I don’t want to be here for nothing.“ Though you didn’t think the same way, you wanted to see what the two were capable off. They were really good fighters, and eventually they killed the demons. You threw a look at Jace, and then walked over to them. „Y/N, wait!“ Jace called, but you were just too curious. „Who are you?“ The brothers looked over to you, both with confusion in their eyes. Then the younger one spoke „I’m Sam Winchester, and this is my brother Dean…who are you?“ You noticed Jace walking up to you. „Winchester? Y/N, aren’t those the ones who started the apocalypse?“ You breathed in sharply. Jace was right, you heard so much about the two brothers who set Lucifer free. Sam looked really uncomfortable, Dean just huffed. You took a closer look at Dean. You couldn’t help but notice that although he was covered in blood, he was really handsome. He had these intense green eyes that you couldn’t stop staring at. „Are you okay? You crashed against the wall pretty hard. “, you asked him. He looked at you again with this curious look that got him in this situation in the first place. „Yeah I’m fine, it’s not that bad. “Then he said „So you know who we are, but who are you? You stormed into the room and saved our asses like some kind of ninjas. How come we never heard of you from other hunters?” Jace laughed out loudly. „That’s because we’re not hunters. We’re Nephilim, or Shadowhunters, whatever you like to call us“, he laughed at them. At that, Sam and Dean looked really surprised. “Nephilim? But...aren’t those the children of angels and humans?” Sam asked with really big eyes. That made you smile. “Not exactly. We have half human and half angel blood, but none of our parents were angels. We were created by the archangel Raziel. It’s kind of a long story.” Jace looked at you angrily. “It’s a story no one’s supposed to know, Y/N. Those are still mundanes, if you may remember.“ You rolled your eyes as far up as you could. You realised that the Winchesters were still staring at you with open mouths. They looked at each other with disbelief. “I think Cas has some explaining to do,” Dean muttered. “Who’s Cas?” you asked, because you’ve heard this name twice already. 

WHOOSH. There was a fluttering sound behind your back, you spun around and held your seraph blade to the intruder’s throat. “Hello. I’m Castiel,” the man said with a gravelly deep voice. He had dark dishevelled hair, really blue eyes and wore a trench coat. Dean grinned and explained “He’s an Angel of the Lord.” Castiel nodded approvingly. “Why are you holding a knife against my throat?” he asked, turning his head to the side like a confused puppy. “Angel, yeah sure,” Jace huffed. He looked at Castiel with a deadpan expression. “Who are you really?” He started to raise his blade impatiently. “Do you know how many Shadowhunters have actually ever seen an angel? They don’t give a damn about us. So if you really are an angel, please let me know, because I really want to punch one in the face for making us do their dirty work.” Jace said all this without making even one facial expression, a skill that you were always quite jealous of. Castiel shifted uncomfortably from one foot to the other. “It’s not dirty work. You were gifted with angelic abilities to protect the world from evil. We need someone to watch out on our behalf, when we cannot interfere.” You looked at him with your mouth hanging open. “Are you seriously telling me you’re an angel?” He looked at you again. “Of course. Why would I lie to you?” he asked with such sincerity that you were tempted to believe him. Jace grabbed your arm and pulled you away from the three guys.  
“These people are crazy. They set Lucifer free, we cannot possibly trust them,” he whispered really upset. “But Jace, what if he really is an angel? He doesn’t seem to be lying.” Jace rolled his eyes. “So what if he is. Angels are dicks!” “Exactly my words!” Dean shouted over to you. Jace glared at him, and Dean’s grin faded. He lowered his voice again. “I think we should go back to the Institute. The Clave probably would want to know the Winchesters are in town.“  
“Jace...”  
“I don’t like mundanes meddling with my business. We wanted to get important information out of this mission, and these morons ruined everything. I don’t care if we report them, but they have to leave right now or I will make them,” he said with a cold look in his eyes. He really could be an asshole when he wanted to. You sighed. “Fine, I’ll talk to them” You walked over again, and were greeted with curious looks. “You need to leave right now or Jace will get really angry,” you delivered the message, not really convinced yourself. Actually, you wanted to know more about these three strange men. Sure, you heard stories, but there were always lots of rumours cursing through the Downworld. You wanted to know what was real. The three guys exchanged a quick look, but then turned to the exit. Dean turned back to you, and gave you a small piece of paper. “If you want to know more about the angels, you should come to this address. We’ll be in town for a few days“ Then he left. Now it was only Jace and you in the room. You looked at the piece of paper, with a smudged address written on it, and then up to Jace, who stood in the middle of the room with his arms crossed and eyebrows raised.  
“So, what will you do?”


End file.
